Self-locking rudder bar for aircraft



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N o D D A L M Aug. 26, 1924.

SELF LOCKING RUDDER BAR FOR AIRCRAFT Filed May 11, 1923 2 Sheets-Sheet l Aug. 26, 1924.

I. M. LADDON SELF LOCKING RUDDER BAR FOR AIRCRAFT Filed May 11, 1923 2 Sheexa-Sheet 2 s wbzwi Patented Aug. 26, 19240 UNITED STATES ISAAOMACHLIN LADDON, OF DAYTON, OHIO.

SELF-LOCKING BUDDER BAR FOR AIRCRAFT.

Application filed Kay 11, 1923. Serial No. 638,250.

To all? whom it may concern:

Be it known that I, ISAAC M. LADDON, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Self-Locking Rudder Bars for Aircraft, of which the following is a specification.

This invent-ion relates to a self-locking rudder bar for aircraft.

The broad object of the invention is to provide simple and reliable means whereby the rudder or steering bar which controls the vertical rudder of an airplane for example, becomes automatically locked in any position where it is left by the aviator when he removes his feet from the rudder bar. He may thus set the rudder bar and vertical rudder in any desired position, where they will remain locked until he again operates the rudder bar with his feet.

A further object of the invention is to provide emergency means whereby in the event of the locking mechanism becoming jammed or otherwise inoperative, the said rudder bar locking means may be immediately rendered ineffective, after which the rudder bar may be operated in the usual way unassisted by the locking means.

With the above and other objects in view, the invention consists in the novel construction, combination and arrangement herein fully described, shown and claimed.

In the accompanying drawings.

Figure 1 is a plan view showing the rudder bar, its mounting, and the rudder bar locking means, also the emergency releasin means.

igure 2 is a rear elevation of the same looking toward the front of the aircraft.

Figure 3 is a vertical transverse section taken on the line A-A of Figure 1.

In carrying out the present invention I employ a rudder bar 5, preferably in the form of a metal tube of any suitable diameter, gauge and length. Secured in fixed relation to the rudder bar 5 are pedals 6 and on account of said pedals bearing a fixed relation to the rudder bar it will be seen that pressure on either one of said pedals will tend to turn the rudder bar about its longitudinal axis, the pedals 5 being oil'set upwardly from the rudder bar as shown in Figures 2 and 3.

The rudder bar 5 is mounted for turning movement on a stationary base 7, which is shown of frusto-oonical formation, said base containing bearings 7' and 8 for a normally vertical tubular shaft 9 upon the upper end of which is secured in any suitable manner as by means of a key 10, abearing yoke 11 which is therefore movable about the axis of the shaft 9.

The bearing yoke 11 is shown of triangular formation and provided with two arms or forks 12, having bearings 13 in which the rudder bar 5 is journaled and adapted to rock on its longitudinal axis.

Fastened centrally to the rudder bar 5 is a locking dog or rack-faced collar 14, the teeth 15 of which are movable into and out of engagement with the teeth 16 of a sector 17. The sector 17 is normally held stationary and it will now be apparent that when the teeth 15 and 16 are in engagement, the yoke '11 is prevented from turning about the axis of the shaft 9 and therefore the rudder bar 5 is locked against steering movement. It may be here noted that the rudder bar 5 is provided adjacent to the opposite extremities thereof with clips 18 adapted to receive the control cables from the vertical rudder of the machine so that when the rudder bar 5 is turned about the axis or shaft 9, a corresponding turning movement is imparted to the vertical rudder.

In order to hold the sector 17 normally stationary, the latter is provided with a rearwardly extending arm 19 having a tapered hole 20 therethrough to receive an emergency locking and releasing pin 21, having a head 22 and a tapered portion which fits into the tapered hole 20 in the arm 19 of the sector and also into a correspondingly sha ed socket in an anchor block 23, which is astened to the stationary base 7 as shown in Figure 3. The pin 20 is also formed with an annular groove 24 into which projects the inner end of a key or pin 25. The key 25 is held in engagement with the groove 24 by a backing spring 26 behind which is an adjustable screw plug 26 for properly tensioning the spring 26, which yields to pressure against the key 25. This permits the pin 21 to be removed, thereby releasing the sector which may then turn freely about the axis of the shaft 9, rendering the rudder bar locking mechanism ineffective. This expedient is resorted to only when the rudder bar locking means becomes jammed or the sector 17, upon removmg pressure from the pedals 6, the rudder bar 5 is rocked in the reverse direction by means of one or more return springs 28 so as to cause the member 14 to again engage the sector 17 and lock the yoke 11 so as to prevent steering movement of the rudder bar. The springs 28 are shown as encircling the rudder bar 6 and secured at one end to the rudder bar and at the other end to the forks or arms of the yoke 11.

From the foregoing description taken in connection with the accompanying drawings it will now be understood that the rudder bar may be rocked on its longitudinal axis by pressure on either foot of the pilot. Upon removing his foot or feet from the edals the rudder bar is automatically ocked as is also the vertical rudder of the.

craft. Upon again applying pressure against the pedal or pedals, the rudder bar is automatically unlocked. In case the locking mechanism should become inoperative for any reason whatsoever, the emergency pin 22-is removed, thereby freeing the sector which forms an element of the locking mechanism and thereafter the locking mechanism is rendered ineffective. This eliminates danger in case of any damage to the looking mechanism. The invent10n is adapted for use on either single or multi-motored airplanes and other types. of aircraft.

'1 claim:

1. A selflocking rudder bar for aircraft comprising a stationary base, a rudder bar mounted for pivotal movement on said base and capable of a rocking movement about its longitudinal axis, and rudder bar locking means between the rudder bar and base, said locking means being thrown into and out of operation by such rocking movement of the rudder bar.

2. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar mounted for pivotal movement on said base and capable of a rockin movement about its longitudinal axis, and rudder bar look ing means between the rudder bar and base, said locking means being thrown into and out of operation by such rocking movement of the rudder bar and normally held in locked position by yieldable means.

3. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar mounted for pivotal movement on said base and capable of a rocking movement about its longitudinal axis, rudder bar locking means between the rudder bar and base thrown into and out of operation by such rocking movement of the rudder bar, and emergency means for releasing an element of the locking means to render the latter ineffective.

4. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar mounted for pivotal movement on said base and capable of a rocking movement about its lon itudinal axis, rudder bar locking means etween the rudder bar and base thrown into and out of operation by such rocking movement of the rudder bar, said locking means including a normally stationary element, and emergency means for releasing .said stationary element to render said locking means ineffective.

, 5. A self-locking rudder bar for aircraft comprisin .a stationary base, a rudder bar mounted or pivotal movement on said base and capable of a rocking movement about its longitudinal axis, pedals fast on said rudder bar and serving as means for rocking the same on its longitudinal axis, and rudder bar locking means between the rudder bar and base, said locking means being thrown into and out of operation by such rocking movement of the rudder bar.

6. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar mounted for'pivotal movement on said base and capable of a rocking movement about its lon ltudinal axis, manually operable means or rocking said rudder bar on its longitudinal axis, and rudderbar locking means between the rudder bar and base said locking means being thrown into and out of operation by such rocking movement of the rudder bar.

7. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar, a yoke pivotally mounted on said base and having said rudder bar journaled thereon and capable of a rocking movement about its lon itudinal axis, and locking means for sai yoke and rudder bar embodying a locking member on the rudder bar and another locking member having a normally fixed relation to the base, said locking means being thrown into and out of operation by such rocking movement of the rudder bar.

8. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar, a yoke pivotally mounted on said base and having said rudder bar journaled thereon and capable of a rocking movement about its longitudinal axis, and lockin means for said yoke and rudder bar em yingalocking member on the rudder bar and another locking member havin a normally fixed relation to the base, sai locking means being thrown' into and out of operation by such rocking movement of the rudder bar and Ill means for releasing said normally fixed locking member to render the locking means ineffective.

' 9. A self-locking rudder bar for aircraft comprising a stationary base, a rudder bar, a yoke pivotally mounted on said base and having said rudder bar journaled thereon and capable of a rocking movement about its longitudinal axis, and means for lockin and releasing said yoke thrown into and 10 out of operation by such rocking movement of the rudder bar to render said locking means ineffective.

In testimony whereof I afiix my signature.

ISAAC MACHLIN LADDON. 

